b. Secondary progressive MS (SPMS) not responding to at least a year of attempted therapy with one or more of the approved therapies (beta-interferon, glatiramer acetate, natalizumab, mitoxantrone, fingolimod) as evidenced by both: i. an increase of ≥1 EDSS point (if at randomization EDSS ≤ 5.0) or 0.5 EDSS point (if at randomization EDSS ≥ 5.5) in the last 12 months ii. ≥1 clinically documented relapse or ≥ 1 GEL at MRI within the last twelve months.